Bypass air volume control device for combustor used in gas turbine

Abstract

The invention applies to an air bypass control device which can bypass a portion of the compressed air in the space within the casing into the tail pipe connected to a combustion chamber via a control valve and a bypass channel. The invention includes a valve mechanism including a flat sliding ring, and a valve operating mechanism. The valve mechanism intersects a number of bypass air channels each of which is connected to a pipe located in the space inside the casing. A number of openings are arranged in the flat sliding ring for bypassing the air to the bypass air channels. The valve operating mechanism, one end of which is connected to the flat sliding ring, causes the flat sliding ring to rotate back and forth. When the operating mechanism rotates the flat sliding ring, the openings in the flat sliding ring rotate so as to coincide with or move away from the openings of the bypass channels. The control valve mechanism is made up of a flat sliding ring with a number of openings which corresponds to the number of bypass channels, and a ring supporting base which supports the flat sliding ring in such a way that the flat sliding ring can slide freely in the circumferential direction. One side of the openings of the flat sliding ring opens into the space in the casing, and the other side of the openings opens into the opening of the bypass channel when it is rotated.

What is claimed is:  
     
       1. A bypass air control device used in a gas turbine combustor in which a number of combustion chambers with tail pipes are arranged in a pressurized space of a combustor casing, which bypasses a volume of compressed air in said pressurized space fed from a compressor, by diverting the compressed air into the tail pipes via bypass valves and bypass air channels, comprising: 
       a flat sliding ring, which intersects a plurality of the bypass air channels and has a plurality of openings corresponding to openings of said bypass air channels, and  
       a valve operating mechanism to control an opening/closing degree of the openings of said bypass air channels by rotating said flat sliding ring back and forth in a circumferential direction.  
     
     
       2. A bypass air control device used in a gas turbine combustor according to claim  1 , wherein said valve operating mechanism comprises said flat sliding ring having a number of said openings which corresponds to the number of said bypass air channels, and a ring supporting base which supports said flat sliding ring in such a way that said flat sliding ring can slide freely in the circumferential direction, and one side of said openings of said flat sliding ring opens to said pressurized space to conduct a portion of said compressed air into said openings of said bypass channels. 
     
     
       3. A bypass air control device used in a gas turbine combustor according to claim  1 , wherein said valve operating mechanism includes a connecting rod connected at one end to said flat sliding ring through a pivot support and another end extending to an outer surface of the combustor casing so as to rotate said flat sliding ring back and forth through a certain angle when an actuator moves the connecting rod back and forth, 
       whereby the openings in said flat sliding ring rotate to coincide with or move away from said openings of said bypass air channels when said valve operating mechanism rotates said flat sliding ring through the angle in order to control an overlapped area of said openings of both said flat sliding ring and said bypass air channels.